Apparatus and process for production of liquid fuel from biomass

ABSTRACT

The liquid fuel synthesizing apparatus ( 1 ) for efficient synthesis of liquid fuel from biomass, such as plant for a raw material, comprised of reactors ( 2 ) with a catalyst incorporated therein, coolers ( 3 ) for cooling of synthesized gaseous matter and extracting of liquid fuel, and temperature adjustment means ( 7 ) for regulating by heat exchange any unreacted gas after recovery of liquid fuel to reaction temperature suitable for liquid fuel gas synthesis, wherein the reactors, the coolers and the temperature adjustment means are arranged multistage inline-straightly along gas flow. The temperature adjustment means ( 7 ) and the reactors ( 2 ) are disposed in the constant temperature room ( 8 ) in parallel. The coolers ( 3 ) are disposed apart from the constant temperature rooms ( 8 ).

TECHNICAL FIELD

The present invention relates to an apparatus and a production processfor synthesizing liquid fuel from biomass such as plants as a rawmaterial.

TECHNICAL BACKGROUND

When considering the shortage and depletion of oil resources and theglobal warming issue mainly due to CO₂, the importance of the selectionand development of the substitutes cannot be overstressed. Since along-term forecast shows that an enormous amount of substitutes isrequired, large expectations have been placed, from a quantitativeviewpoint, on the production of synthetic fuel made from biomass as araw material.

As in a case where natural gas and coal are used as raw material, liquidfuel (e.g., methanol, DME (dimethyl ether), or hydrocarbon by F-T(Fischer-Tropsch) process) can be obtained from synthetic gas (H₂+CO)obtained by using biomass as a raw material to gasify the material.These liquid fuels synthesized from biomass have advantages, including:(1) these fuels are obtained through the accumulation of solar power andcan be subjected to cyclic regeneration, (2) biomass as a raw materialis not unevenly distributed all over the world and thus can be expectedto be available in the future in an amount equal to that of the currentconsumption of petroleum, (3) these fuels are storable and portable in afavorable manner, and (4) these fuels do not increase CO₂ in air anddoes not include a sulfur content and thus is clean for example.

However, as described by the present inventor in Non-patent Document 1,in spite of the fact that a great number of researches and developmentshave been made, the current situation where the production of syntheticfuel using biomass as a raw material has not been realized at anindustrial scale is due to the following reasons. First, biomass has notbeen highly recognized until recently. Secondly, since biomass includesoxygen, the calorific value is low and thus such synthetic gas requiredfor the production of liquid fuel could not be obtained that had a highcalorific value and that included H₂ at a high content ratio. Non-patentDocument 1 is a document by the present inventors describing the priorart (regarding large-scale apparatus).

A process for producing liquid fuel from synthetic gas obtained bygasifying biomass is basically the same process for producing liquidfuel from fossil fuel such as natural gas or coal as raw material.Specifically, a production process using natural gas as a raw materialis mainly composed of a step of converting fossil fuel as raw materialto synthetic gas of carbon monoxide and hydrogen for example tosubsequently remove impurities such as sulfur and unwanted matters suchas CO₂ in synthetic gas, a step of causing the resultant synthetic gasto react under the existence of a catalyst to convert the gas to liquidfuel, and a step of refining liquid fuel to have a property of a targetfuel to obtain a product.

Gasification methanol synthesis, which is one of processes for producingliquid fuel from biomass, has been subjected to many experiments and hasreached an industrial scale up to the step of gasifying biomass.However, the gasification methanol synthesis has not reached a level atwhich methanol is synthesized efficiently. The reason is that biomasshas a low calorific value as described above, thus failing to providesynthetic gas having a high calorific value required for the methanolsynthesis. However, advances have been seen even in the biomassgasification technique and thus some promising aspects have been foundin the production of synthetic gas (e.g., Patent Document 1).

Another point to which attention should be paid for the production ofsynthetic gas is a capacity. For example, a current methanol synthesisapparatus using natural gas as a raw material has a production scale of1,000 to 2,000 tons/day and is operated, from the viewpoints of energyefficiency and economic efficiency, at a high pressure of 5 MPa or moreand frequently at 6 MPa or more. However, a biomass integration densityin Japan in particular is not so high. Thus, a methanol productionprocess and a production apparatus are required that can cope with aproduction scale of 0.1 to 100 tons/day one digit to four digits smallerthan the above methanol production scale, that are small in size, andthat can be operated easily at a low pressure.

As a methanol production technique that is small and that can beoperated easily at a low pressure, the technique of Patent Document 2has been already known. This technique is suggested by the presentinventors and discloses a methanol synthesis apparatus in which methanolsynthetic reactors are serially coupled at a plurality of stages.Although this invention discloses that the same operation is repeated atmany stages, the existence of the reactors at a plurality of stages hasprevented these reactors from having an appropriate temperature adjustedfor reaction. Furthermore, due to the longitudinal layout in which thereactors are arranged in the longitudinal direction from the top tobottom, an exchange of catalysts has required the disassembly ofreactors in all stages and thus has required a long-time maintenance andthus an inconvenience also has been caused in the operation schedule.Furthermore, due to the layout in which temperature controlling devicesare parallely arranged in all stages, a disadvantage has been causedthat the resultant apparatus is complicated.

Furthermore, when liquid fuel gas is synthesized from synthetic gasobtained by gasifying biomass (e.g., when methanol gas is synthesized),higher concentrations of H₂ and CO in the synthetic gas provide a higheryield of methanol gas. If these concentrations are low, methanol gascannot be synthesized at a high yield. Thus, in order to efficientlyproduce methanol from biomass, what is required is, in addition to amethanol synthesis apparatus, a biomass gasification techniqueappropriate for the apparatus and a technique of producing synthetic gasincluding H₂ and CO or CO₂ at a high concentration in particular.

Furthermore, when considering the use of biomass as an energyplantation, in order to increase the amount of the production ofmethanol per a unit area, it is advantageous to use, from among thesynthetic gas obtained by the gasification of biomass, not only carbonmonoxide but also carbon dioxide as a raw material for synthesizingliquid fuel. In recent years, a catalyst by which methanol can besynthesized from carbon dioxide and hydrogen has been developed. Thiscatalyst has a higher performance than that of a catalyst for methanolsynthesis from carbon monoxide and hydrogen. Furthermore, only syntheticgas obtained from biomass cannot provide a sufficient amount of hydrogento synthesize methanol from carbon dioxide. It has been clarified that,as a system that can supplement this shortage, a system is effectivethat uses electrolytic hydrogen using hydraulic power generation,wind-power generation, and photovoltaic power generation for example.

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2004-051718 Patent Document 2: Japanese Unexamined PatentApplication Publication No. 2005-132739

Non-patent Document 1: Kusaki Baiomasu Karano Gousei Gasu Seizou ToEkitai Nenryou Gousei (Journal of The Japan Institute of Energy, volume81, No. 12, p. 1063-1068)

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

In view of the above situation, it is an objective of the presentinvention to provide a process for producing liquid fuel from syntheticgas obtained by gasifying biomass such as plants as a raw material and aliquid fuel synthesis apparatus that is small in size and operates in afavorable manner and that achieves a high liquid fuel yield even at alow pressure operation. It is another objective of the present inventionto provide a liquid fuel production apparatus including a biomassgasification apparatus highly compatible with a liquid fuel synthesisapparatus.

Means for Solving Problem

The liquid fuel production process of the present invention is a processfor producing liquid fuel from synthetic gas including hydrogen andcarbon monoxide obtained by gasification of biomass. This processincludes: a first step of causing the synthetic gas to have a contactwith catalyst while being pressurized at a pressure of 0.5 to 5 MPa tosynthesize liquid fuel gas; a second step of liquefying the liquid fuelgas to collect the gas to separate the gas from unreacted synthetic gas;a third step of again causing the unreacted synthetic gas to have acontact with catalyst while being pressurized at a pressure of 0.5 to 5MPa to synthesize liquid fuel gas; and a step of repeating the firststep and the third step. Liquid fuel includes liquid hydrocarbon fuelsuch as methane, ethane, or propane and alcohol fuel such as methanol.

The apparatus for synthesizing liquid fuel from biomass according to thepresent invention includes: a plurality of reactors and a plurality ofcoolers that are arranged in a serial manner, the reactors and thecoolers are connected to one another via a synthetic gas supply pipe anda reaction gas derivation pipe, and the coolers include liquid fuelcollection pipes.

The apparatus for producing liquid fuel from biomass according to thepresent invention includes: a biomass supply hopper; a gasificationreaction apparatus; and a liquid fuel synthesis apparatus. Thegasification reaction apparatus includes therein a secondarygasification reaction pipe and a primary gasification reaction room thathas a gasification agent supply line linked to the secondarygasification reaction pipe. The liquid fuel synthesis apparatus iscomposed of a plurality of reactors and a plurality of coolers that arearranged in a serial manner, the reactors and the coolers are connectedto one another via a synthetic gas supply pipe and a reaction gasderivation pipe, and the coolers include liquid fuel collection pipes.The biomass supply hopper is connected to the gasification reactionapparatus by being connected to the primary gasification reaction roomvia a biomass supply line. The gasification reaction apparatus isconnected to the liquid fuel synthesis apparatus via a synthesis rawmaterial gas supply line.

According to the process for producing liquid fuel of the presentinvention, the synthesis of liquid fuel gas by synthetic gas and aliquid fuel synthesis catalyst, the liquefaction of synthesized liquidfuel gas, and a process for separating unreacted synthetic gas areperformed repeatedly. Thus, the synthesized liquid fuel gas is removedfrom the reaction system at every synthesis.

When the liquid fuel gas is hydrocarbon gas, the equilibrium relation ofFischer-Tropsch reaction shown by the following formula is promoted inthe arrow direction. By repeating this a plurality of times, thesynthesis yield of hydrocarbon gas can be increased.

(2n+1)H₂ +nCO→C_(n)H_(2n+2)+H₂O

Fischer-Tropsch reaction generally uses a catalyst of a compound of ironor cobalt. For example, a cobalt-supporting catalyst can be obtained byimpregnating cobalt nitrate in silica gel to subsequently dry the silicagel to burn the silica gel at 400 degrees C. for 2 hours.

When the liquid fuel gas is methanol gas, this means that theequilibrium relation of the methanol synthesis reaction shown by thefollowing formula is promoted in the arrow direction. By repeating thisa plurality of times, the synthesis yield of methanol can be increased.

2H₂+CO→CH₃OH

Currently, methanol synthesis is operated by mainly copper or zinc-basecatalyst and at 200 to 260 degrees C. and at a high pressure of 5 MPa ormore and frequently 6 MPa or more. The reason why the synthesis isperformed under a high pressure condition is that, due to theequilibrium relation of the methanol synthesis reaction using acatalyst, a low pressure condition causes a low methanol yield (i.e., alow rate at which hydrogen and carbon monoxide are converted tomethanol). However, such an operation under a high pressure is desirablyavoided because, setting aside a large-size apparatus, a small-sizesynthesis apparatus subjected to an operation at a high pressure resultsin a high load on the apparatus and the safety may be insecure.

The liquid fuel synthesis apparatus of the present invention includes: aplurality of reactors filled with catalysts and a plurality of coolersthat are arranged in a serial manner. The reactors and the coolers areconnected to one another via a synthetic gas supply pipe and a reactiongas derivation pipe. The coolers include liquid fuel collection pipes.By the liquid fuel synthesis apparatus of the present invention, thesynthesis yield of liquid fuel can be increased even under a lowpressure.

A catalyst included in the reactor is not particularly limited and maybe, for example, a catalyst used for methanol synthesis (e.g., zincoxide, Cu/ZnO, Al₂O₃, ZrO₂, copper, zinc, aluminum, germanium, ormanganese-base catalyst).

The synthetic gas separated in the final reactor still includeshydrogen, carbon monoxide, and hydrocarbon. These substances may becirculated to be used as synthetic gas or also may be used as gas fuel.

Any cooler may be used so long as the cooler has a function to cool thegaseous liquid fuel obtained through the reaction to a temperature equalto or lower than the liquefaction temperature. The cooler may be the onefor subjecting gaseous cooling medium or liquid cooling medium to a heatexchange or also may be stored in a cooling bath filled with coolingwater of a predetermined temperature or lower. Gaseous methanol iscooled by the cooler to have a temperature equal to or lower than theliquefaction temperature and is liquefied. The liquefied liquid fuel isremoved from the reaction system by the liquid fuel collection pipe andis collected.

The liquid fuel synthesis apparatus of the present invention has atemperature adjustment means for adjusting the temperature of thereactor to an appropriate temperature.

The reactors also may be parallely arranged in a constant temperatureroom in which the temperature can be adjusted.

As described above, the synthesized gaseous liquid fuel is liquefied bybeing cooled and is separated from unreacted synthetic gas and iscollected. Unreacted hydrogen and carbon monoxide in the separatedsynthetic gas is sent to the next reactor and is further synthesizedinto liquid fuel gas. However, even when the unreacted synthetic gascooled in the cooler is sent to the next reactor, this unreactedsynthetic gas includes local low-temperature parts in which anappropriate synthetic reaction is prevented from being promoted. Thus,it is important to heat the synthetic gas at the inlet of the reactor tohave an appropriate temperature. Specifically, although not limited to aparticular configuration, it is preferable that the previous stage ofthe reactor has a heat exchanger or the reactor is stored in a constanttemperature room in which the temperature can be adjusted to therebyperform a stable adjustment of the temperature.

The reactor also may be the one that maintains the temperature in thereactor at an appropriate temperature by subjecting the reaction heatgenerated by the synthetic reaction to a heat exchange with thesurrounding atmosphere.

The temperature in the constant temperature room can be controlled by agaseous medium or air, or also by water vapor generated by alow-pressure boiler, for example. Alternatively, the heat dissipationcapability also may be improved by circulating water vapor of 10atmospheric pressure or less by a circulator to improve the circulationflow rate. When water vapor of 10 atmospheric pressure or less is used,vapor having absorbed heat discharged from the constant temperature roommay be cooled by an air cooler for example at the outside of theconstant temperature room to merge the vapor with new pressurized watervapor to circulate the resultant vapor.

In the case of the current large-size apparatus, the methanol synthesisreaction causes significant heat generation (21.7 kcal by generation of1 mol of methanol). Thus, it is required to remove the generated heat tomaintain a fixed reaction temperature. Since this heat removal methodhas an influence on the entire energy efficiency, various methods havebeen tried. A typical heat removal method currently performed in theindustrial field is called a quench method according to which aplurality of catalysts are provided at a plurality of stages among whichcool raw material gas is introduced. This method is simple but causes ahigh gas flow rate to thereby increase the resistance loss in the flowand also requires a large amount of catalyst. In the case of asmall-size apparatus to which the present invention can be applied onthe other hand, the situation is different from that of a large-sizeapparatus. Specifically, the rate of heat dissipation from the surfaceof the reactor increases in proportion to the heat generation by thereaction. Thus, the temperature of the catalyst section can bemaintained at a fixed temperature by the heat dissipation from the outerface of the container of the reactor. This method is very advantageousin the gas flow rate and the catalyst amount.

However, there may be a case where not cooling but heating is requiredat the outer side of the reaction or a case where a small amount ofcooling is required when a dissipation rate is insufficient compared toheat generation. This also may be influenced by the outside temperatureor air flow for example. According to the present invention, in order tocope with any case, the constant temperature room stores therein areactor to thereby maintain appropriate operation conditions, thusrealizing a stable and reliable apparatus. Alternatively, fins forexample also may be provided at the surface of the reactor to therebyefficiently perform a heat exchange.

The liquid fuel synthesis apparatus of the present invention isstructured so that the reactor has an outer diameter of 20 cm or lessfor example. The liquid fuel synthesis apparatus is structured toinclude: a plurality of reactors for subjecting reaction heat generatedby synthetic reaction to a heat exchange with the surrounding atmosphereto maintain an appropriate inner temperature and a plurality oftemperature adjustment means for maintaining the gas at the inlet of thereactors at an appropriate temperature. The reactors and temperatureadjustment means are parallely arranged in the constant temperatureroom.

The reason why the reactor has a diameter of 20 cm or less andpreferably 15 cm or less is that a reactor having a large diameter makesit difficult to control the temperature of the interior and thus thecenter may be excessively heated due to reaction heat. On the otherhand, a reactor having an excessively-small diameter causes a greatnumber of reactors or an apparatus having high reactors, which isdisadvantageous in cost. The cross-sectional area of the interior of thereactor is proportional to the square of the pipe diameter but thesurface area of the outer wall of the pipe is merely proportional to thepipe diameter. Thus, a smaller pipe diameter is more advantageous forheat dissipation but causes a difficulty to fill catalyst in the pipe.To prevent this, in order to improve the heat dissipation capability pera catalyst volume in the reactor, no-catalyst spaces in which catalystis not filled also may be provided with appropriate interval and lengthin the axial direction of the reactors.

Alternatively, a shell tube heat exchanger-type boiler also may be usedthat performs the cooling of the reactors or the constant temperatureroom by boiler water. In this case, the tube-side has the reactors areplaced at tube side and the shell has the flowing boiler water. Theboiler water itself is subjected to a liquid level control and apressure control for maintaining a fixed pressure by a pressure controlvalve provided in a line sending discharged vapor. As a result, theshell-side temperature is maintained at a temperature at which vaporsaturates. Specifically, the reactor-side temperature of about 250degrees C. and the boiler-side temperature of about 230 degrees C. canprovide the in-shell pressure of about 28 atmospheric pressure.

Instead of parallely arranging reactors at multiple stages, anotherlayout is also possible where reactors are superposed at stages in thelongitudinal direction. However, this longitudinal layout requires thereactors in all stages to be disassembled, which is disadvantageous inthe maintenance and operation schedule, when a deteriorated catalystneeds to be exchanged with the new one. In addition, this longitudinallayout is also disadvantageous in that the apparatus is complicated andthe assembling operation is difficult.

In contrast with this, according to the configuration of the presentinvention, the heating means and reactors at the respective stages areparallely arranged on a single floor face. Thus, when a certain catalystis deteriorated, the deteriorated catalyst can be exchanged with the newone by opening only the reactor having the deteriorated catalyst throughthe upper section, which is significantly advantageous in themaintenance. The apparatus having this configuration also can beassembled easily.

The liquid fuel production apparatus of the present invention isstructured so that a liquid fuel synthesis apparatus is linked to abiomass supply hopper and a gasification reaction apparatus forproducing synthetic gas.

The gasification reaction apparatus has the following characteristics. Agasification space is provided in which the ground biomass supplied fromthe biomass supply hopper receives water vapor and is subjected to agasification reaction. Without supplying oxygen to the gasificationspace, the gasification space is blocked by a partition wall from theouter heating space. The ground biomass is heated mainly by heattransfer by radiation. By using the heat for reaction heat, agasification reaction between water vapor and biomass is caused tooccur.

The gasification reaction apparatus includes therein a secondarygasification reaction pipe and a primary gasification reaction room thathas a gasification agent supply line linked to the secondarygasification reaction pipe. The primary gasification reaction room islinked to the biomass supply hopper via the biomass supply line and isalso linked to the liquid fuel synthesis apparatus via the synthetic gassupply pipe.

The synthetic gas obtained by the gasification reaction apparatusincludes a great amount of hydrogen gas and carbon monoxide gas requiredfor the synthesis of liquid fuel and can be obtained in a clean statefree from tar. Thus, the liquid fuel synthesis yield is high and theapparatus can be stably operated without having a mechanical problem.

Conventionally, gasification of biomass has been performed by cuttingwood to have a chip-like shape to supply the wood chips to a fixed bedor fluid bed-type gasification furnace to gasify the chips by agasification agent of (O₂+H₂O). When this phenomenon is considered fromthe viewpoint of combustion, this phenomenon means that oxygen and woodare combusted to generate hot gas to use this hot gas to thereby subjectthe remaining wood to pyrolysis. This method provides a small amount ofeffective hydrogen and carbon monoxide and causes the generation of agreat amount of trouble-causing polymeric tar. In order to decomposethis tar, oxygen must be blown into tar to thereby subject tar to thesecondary combustion. In this case, effective hydrogen and carbonmonoxide cannot be allowed to remain. Specifically, when biomass havingonly a calorific value ½ to ⅓ smaller than that of a fossil fuel is usedas a raw material, the synthesis of liquid fuel is very difficult.

The present inventors have made a success in using a new gasificationmethod to minutely grind biomass raw material to mix the resultantpowders with a gasification agent of (O₂+H₂O) in such a manner that theoxygen concentration of the gasification agent is reduced to anextremely-low value and is finally reduced to the oxygen concentrationof zero to thereby achieve a jet flow floor (where microparticles arefloating), thereby providing high-calorie gas. Furthermore, a benchscale experiment apparatus using this method has demonstrated thattransparent and colorless clean gas including a great amount ofeffective hydrogen, carbon monoxide, and methane could be obtainedwithout causing any tar or soot. This experiment also has demonstratedthat liquid fuel could be synthesized from these gases.

The raw material was powders obtained by drying sorghum to subsequentlygrind sorghum and minute-and-dry spirulina powders. The former andlatter raw materials showed methanol yields as a weight ratio to the rawmaterials of 49% and 60% that were calculated based on the gascomposition. Thus, a yield of 50% can be expected even when an actualplant is assumed and the plant power is deducted. Methanol has a highercalorific value than that of biomass. Thus, when the methanol yield isevaluated based on the calorific value, the yield of 50% as a weightratio corresponds to a yield of 60% calorific value.

According to this new gasification method, raw material is finelyground. Thus, not only large trees but also plants can be used as a rawmaterial. This method does not need to consider sugar or starch as in afermentation process.

The resultant gas has a composition significantly changing depending onthe molar ratio [O₂]/[C] between carbon in the biomass and oxygen in thegasification agent. When complete combustion of [O₂]/[C]=1.0 is reached,the composition is naturally only CO₂. As [O₂]/[C] is smaller, thecompositions of H₂ and CO increase and the methanol yield alsoincreases. When [O₂]/[C]=0 is established, the methanol yield ismaximum. In this case however, all the heat required to maintain thetemperature field of the gasification furnace is provided from the outerside.

The methanol production apparatus of the present invention is structuredso as to improve the methanol yield per biomass raw material, hydrogenobtained by water electrolysis by the power by renewable energy otherthan biomass is compensated to raw material gas for methanol synthesis.

According to the above configuration, departing from the basic objectiveof the present invention of the use of renewable energy, the compensatedhydrogen can be used to convert carbon monoxide and carbon dioxide insynthetic gas to methanol to a maximum extent.

According to the methanol production apparatus of the present invention,in order to improve the methanol yield per biomass raw material,hydrogen obtained by water electrolysis, which power is obtained byrenewable energy other than biomass, is compensated to the raw materialgas for methanol synthesis. The synthetic gas obtained from the biomassincludes hydrogen and carbon monoxide as well as carbon dioxide.

By the above configuration, carbon dioxide that may be raw material formethanol synthesis can be further increased by a certain amount, thusfurther increasing the methanol yield per biomass. In this case,however, the methanol reactor must use such a catalyst by which carbondioxide can be used as a raw material for the synthetic reaction asdescribed later.

EFFECT OF THE INVENTION

According to the present invention, by serially arranging a plurality ofreactors, high yield of synthesis liquid fuel gas is obtained since thetemperature of methanol synthesis is maintained continuously in spite ofa low pressure operation, and also the cooling system is simplified soas to prevent getting complex in spite of the existence of the pluralityof reactors. Therefore, an improved apparatus is provided.

By the biomass gasification reaction apparatus of the present invention,synthetic gas suitable for the synthesis of liquid fuel gas can beobtained. This provides an effect according to which the liquid fuelyield is increased to improve the stability and reliability in theoperation of the entire apparatus. Furthermore, synthetic gas containshigher content of carbon monoxide and carbon dioxide by adding hydrogengas obtained by water electrolysis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a fuel gas synthesis apparatus according to amultistage basic experiment according to the first embodiment of thepresent invention.

FIG. 2 illustrates a graph showing the methanol conversion rate of themultistage basic experiment apparatus according to the first embodimentof the present invention.

FIG. 3 illustrates an example of a fuel gas synthesis apparatusaccording to the second embodiment of the present invention.

FIG. 4 schematically illustrates a process flow according to the secondembodiment of the present invention.

FIG. 5 illustrates the configuration of the entire gasification reactionapparatus according to the third embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a high-temperature hot gasgeneration apparatus that is a constituent element of a gasificationreaction apparatus according to the third embodiment of the presentinvention.

FIG. 7 is a cross-sectional view illustrating the configuration of abiomass gasification reaction apparatus that is a constituent element ofthe gasification reaction apparatus according to the third embodiment ofthe present invention.

FIG. 8 illustrates a graph showing a synthetic gas composition ratio ata gasification reaction temperature of 900 degrees C. of thegasification reaction apparatus according to the third embodiment of thepresent invention.

FIG. 9 illustrates the configuration of the entire gasification reactionapparatus according to the fourth embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

-   1 Liquid fuel synthesis apparatus-   2 Reactor-   3 Cooler-   4 Synthetic gas supply pipe-   5 Reaction gas derivation pipe-   6 Liquid fuel collection pipe-   7 Temperature adjustment means-   8 Constant temperature room-   101 High-temperature hot gas generation apparatus-   102 Combustion furnace-   103 Fire grate-   106 Primary air-   107 Secondary air-   108 Tertiary air-   109 High-temperature combustion gas-   201 Gasification reaction apparatus-   202 Primary gasification reaction room-   203 Secondary gasification reaction pipe-   205 Biomass supply hopper-   206 Coarse powder-accompanying gas supply line-   203 Gasification agent supply line-   A Synthesis raw material gas supply line-   B High-temperature combustion gas supply line

THE BEST MODE FOR CARRYING OUT THE CLAIMED INVENTION

The following section will specifically describe the present inventionwith reference to the drawings. In embodiments, a case where liquid fuelis methanol will be described as an example.

FIG. 1 schematically illustrates a multistage liquid fuel synthesisbasic experiment apparatus that is the first embodiment according to thepresent invention. The liquid fuel synthesis apparatus is structured toinclude a plurality of reactors 2 generally arranged in 3 stages to 10stages. In the shown example, the liquid fuel synthesis apparatus iscomposed of the reactors 2 in 5 stages. These reactors 2 are arrangedserially with regard to the flow of gas.

The upstream-side of the reactor 2 is connected to a synthetic gassupply pipe 4 and the downstream-side is connected to a reaction gasderivation pipe 5 to be linked to a cooler 3. Synthetic gas, which issynthesis raw material of liquid fuel, is supplied from the syntheticgas supply pipe 4 to the reactor 2. The reactor 2 at the mostupstream-side is linked to a synthesis raw material gas supply line Aand receives the supply of synthetic gas. In the case of methanolsynthesis, the reactor 2 for synthesizing liquid fuel is generallyfilled with copper or zinc-base methanol synthesis catalyst. However, inorder to convert carbon dioxide to methanol, the reactor 2 is preferablyfilled with copper, zinc, aluminum, germanium, or manganese-basecatalyst. Although synthetic reaction is achieved by exothermicreaction, heat dissipation from the surface of the container of thereactor 2 enables to maintain the reaction temperature in a range from150 to 300 degrees C. The reaction gas includes methanol in the form ofvapor. By using the cooler 3 to cool the reaction gas sent from thereaction gas derivation pipe 5 to the cooler 3, the methanol vaporincluded in the reaction gas is turned into liquid methanol to therebyremove liquid methanol as methanol through a liquid fuel collection pipe6. The reference numeral 50 denotes a cooling water supply line and thereference numeral 51 denotes a discharge line.

The resultant synthetic gas from which this methanol vapor is removedand which can be further reactive under a chemical equilibrium isintroduced to the reactor 2 of the next stage in which the sameoperation as that performed in the reactor 2 of the previous stage isperformed. Then, the same step is repeated in multiple stages. Thesupplied synthetic gas is finally discharged through an unreacted gasdischarge line 52 to the outside of the reactors.

Next, Experiment 1 showing the usefulness of the present invention wasperformed. Gasification was performed by a stainless steel-madegasification reaction pipe having an inner diameter of 50 mm and alength of 900 mm. Cedar wood powders obtained by grinding ceder to havea particle diameter of about 1 mm were supplied through the upper partof the reaction pipe at a speed of 2 g/minute and gasification agent ofwater vapor was supplied at 8 g/minute. The gasification reactiontemperature was maintained at 1,000 degrees C. by electrically-heatingthe outer side of the reaction pipe. The cleanup of synthetic gas wasperformed by bubbling 0.1N sodium hydroxide solution. This gasificationoperation was continuously performed for one hour and synthetic gas wasstored in a gas tank at an ordinary temperature. The gas in the tank hadthe following composition (volume %) under a dry gas standard.

H₂ 51.3, CO 35.7, CO₂ 7.3, CH₄ 3.1, C₂+2.6

In the above composition, C₂+ represents a component in which onemolecule includes two or more carbons such as ethylene or ethane.

This gas was used as a raw material for methanol synthesis and wasintroduced to a methanol synthesis test apparatus according to the firstembodiment. The reaction pipe is a stainless steel-madepressure-resistant reaction pipe that has an inner diameter of 67 mm anda height of 220 mm and is arranged in five stages. Each reaction pipeincluded a metal container to which 350 cc of copper-base catalyst and350 cc of zinc-base catalyst were filled, respectively. The supply gasflow rate was 2Nl/minute. The gas flow is the same downward flow as thatof FIG. 1 and the outlet of each stage has a reservoir in which gasafter reaction is cooled and methanol is collected as liquid. Thereaction pressure was adjusted to 0.9 MPa and the reaction temperaturesin all of the five stages were adjusted to 200 to 220 degrees C. by aheating heater wound around the outer side of the reaction pipe. Thereaction temperature is generally set in a range from 150 degrees C. to300 degrees C.

The test was performed for 60 minutes. As a result, methanol in crudemethanol could be obtained in an amount of 17.2 g, in spite of such alow pressure, a high yield of 40% (based on an amount of hydrogensupplied to the methanol synthesis apparatus) could be obtained.

Next, as a comparison example, the supply of cooling water was stoppedand, without performing the liquefication and collection of methanolvapor in each stage, the experiment was performed so that only the gasfrom the outlet at the final stage was cooled. The result of thecomparison example shows that the methanol yield was only 4.8 g per 60minutes, thus showing the usefulness of the present invention.

The above experiment result can be summarized by a methanol conversionrate as shown in FIG. 2. FIG. 2 shows a comparison between theperformance B regarding a case where methanol is synthesized throughmultiple stages and the performance C regarding a case where one-stageextraction is used without cooling water flowing in the cooler that doesnot have a cooling function. While the one-stage extraction C shows aperformance at the lower side of the equilibrium conversion rate curveA, the multiple-stage extraction B shows a performance far above fromthis curve A. Specifically, this shows that, a low pressure operationsuitable for a small-size apparatus can provide a greater amount ofmethanol by the adjustment of the chemical equilibrium relation.

Next, Experiment 2 was performed in order to confirm the usefulness ofan addition of a water electrolysis hydrogen production apparatus bynatural energy such as water power or wind power. In Experiment 2,hydrogen gas from water electrolysis was simulated by additionallysupplying the hydrogen gas from a purchased cylinder to the supply gasof Experiment 1 at a flow rate of 0.4 Nl/minute to thereby adjust theH₂/CO molar ratio to 2.0 optimal for the methanol synthesis. The otherstructures in Experiment 2 are the same as those of Experiment 1. As aresult, 24.1 g of methanol could be obtained as expected after 60minutes, i.e., methanol about 40% larger than that in Experiment Example1 could be obtained. The methanol synthesis catalyst in this case wascopper-base, zinc-base, aluminum-base, germanium-base, or manganese-basecatalyst.

Here, a difference in the methanol yield will be shown between a casewhere only synthetic gas is used and a case where hydrogen is mixed insynthetic gas for compensation. The composition vol % of synthetic gasis calculated as an example.

A biomass informal molecular formula is assumed as C1.3H2O0.9 and amethanol conversion rate is assumed as 80%.

Synthetic Gas Composition

H₂: 50%, CO: 20%, CH₄: 10%, C₂H₄: 1%, CO₂: 14%, N₂: 5%

Generally, CO₂ is not used as a main raw material for methanol synthesisbut may be used as a raw material depending on a catalyst (e.g.,copper-base, zinc-base, aluminum-base, germanium-base, or manganese-basecatalyst). This is represented by reaction formulae as shown below.

CO+2H₂→CH₃OH

CO₂+3H₂→CH₃OH+H₂O

Methanol weight yields R in the respective cases can be calculated bythe calculations as shown below.

When hydrogen is not compensated:

R=0.8×(CO)×1.3(C)/[(CO)+(CH₄)+2(C₂H₄)+(CO₂)]=0.8×20×1.3/[(20+10+2+14)]=0.452

Specifically, this means that 0.45 kg of methanol can be obtained from 1kg of biomass. When hydrogen is compensated:

R=0.8×1.3(C)[CO+CO₂]/[(CO)+(CH₄)+2(C₂H₄)+(CO₂)]=0.8×1.3×[20+14]/[(20+10+2+14)]=0.768

Specifically, this means that 0.77 kg of methanol can be obtained from 1kg of biomass.

Next, the second embodiment of the liquid fuel synthesis apparatushaving the main function of the present invention is shown in FIG. 3.The liquid fuel synthesis apparatus is composed of: the reactors 2including therein catalysts and being made of stainless steel; thecoolers 3 for cooling synthesized liquid fuel gas to extract liquidmethanol; and temperature adjustment means 7 for adjusting, by heatexchange, the synthetic gas including an unreacted gas component leftafter the collection of liquid methanol to have a reaction temperaturesuitable for the synthesis. These members are arranged in a serialmanner along the gas flow direction at multiple stages. The temperatureadjustment means 7 and the reactors 2 are stored in a constanttemperature room 8 having a heat insulating structure surrounded by aheat insulating material.

The coolers 3 on the other hand are stored in a cooling bath 53positioned at the lower side of the constant temperature room 8.

Although this example shows a layout in which the constant temperatureroom and the cooling bath are provided at upper and lower sidesrespectively, the constant temperature room and the cooling bath alsomay be arranged to be adjacent to each other if the planar arrangementis convenient.

The constant temperature room 8 is set to have an appropriatetemperature of 150 to 300 degrees C. by a constant temperature roomtemperature adjuster 54 using air and combustion gas. The referencenumeral 55 denotes an air supply line. The reference numeral 56 denotesa combustion gas supply line. The reference numeral 57 denotes adischarge line for air and combustion gas. The cooling bath 53 on theother hand is retained by cooling water to have a temperature of 60degrees C. or less. The reference numeral 58 denotes a supply line forthe cooling water. The reference numeral 59 denotes a discharge line.

Synthetic gas as a raw material of methanol is supplied from agasification reaction apparatus (not shown) via the synthesis rawmaterial gas supply line A. Then, the synthetic gas is heated by thetemperature adjustment means 7 in the constant temperature room 8 tohave a predetermined temperature. Then, the synthetic gas is sent to thereactors 2 where methanol gas is synthesized by an action by catalysts.

Methanol gas and unreacted synthetic gas are sent from the reaction gasderivation pipe 5 to the cooler 3 and only methanol gas is extracted byliquefaction and is collected through the liquid fuel collection pipe 6.On the other hand, unreacted synthetic gas is sent via the synthetic gassupply pipe 4 to the next stage of the temperature adjustment means 7and is further sent to the reactors 2. The reference numeral 60 denotesan outlet line of unreacted synthetic gas.

FIG. 4 schematically illustrates a process flow according to the secondembodiment for carrying out the present invention. In FIG. 4, solidbiomass is firstly gasified to have a gaseous state. Various biomassescan be used including, for example, industrial and agricultural wastessuch as woods, construction waste, bark, paddy straw, or bagasse andkitchen waste frequently including cellulose as a main component.However, the invention is not particularly limited to them. Gasificationagent generally may be water vapor, air, oxygen or the like.

The reference numeral 205 denotes a supply line for biomass as a rawmaterial. The reference numeral 303 denotes a gasification agent supplyline. Gasification agent may be water vapor and carbon dioxide forexample as described later. Carbon dioxide also functions as auxiliaryagent supporting the decomposition and gasification of biomass. Thereference numerals 101 and 201 denote a high-temperature hot gasgeneration apparatus and a gasification reaction apparatus,respectively. However, other known biomass gasification methods also maybe used such as the one using a fixed bed and the one using a fluid bed.

Through gasification, not only hydrogen and carbon monoxide as rawmaterial for methanol synthesis but also valuable hydrocarbon such asmethane, ethylene, or ethane and carbon dioxide are generated. Inaddition to these substances, minor components are also generated thatare a sulfur compound such as hydrogen sulfide or carbonyl sulfide and anitrogen compound such as ammonia or hydrogen cyanide. A sulfur compoundin particular shows toxicity to a methanol synthesis catalyst and thusis optionally removed by known absorbing liquid or adsorption agent. Thereference numeral 400 denotes a cleanup apparatus for this purpose.

The gas thus obtained is once stored in a gas tank 406 and is to be usedas a raw material for producing methanol. Once stored, the synthetic gasis pressurized at a pressure of 0.5 to 5 MPa by a pressurization pump405 and is guided to the liquid fuel synthesis apparatus 1. Thereference numeral 6 denotes a liquid hydrocarbon collection pipe. Thereference numeral 414 denotes a circulation line for unreacted gas to agas tank. This gas includes unreacted hydrogen, carbon monoxide as wellas hydrocarbon such as methane or ethylene and carbon dioxide and thuscan be used as fuel for a gas engine. When the only purpose is toproduce methanol, the gas may be further subjected to processesgenerally used in the chemical industry such as a steam reforming forconversion to hydrogen and carbon monoxide and the use of a shiftreactor for adjusting a ratio between hydrogen and carbon monoxidedeviating from a range suitable for methanol synthesis.

Next, FIG. 5 illustrates a configuration example of the entire liquidfuel production apparatus according to the third embodiment for carryingout the present invention. Specifically, the liquid fuel productionapparatus is composed of: a biomass supply hopper 205; a gasificationreaction apparatus 201; and the liquid fuel synthesis apparatus 1. Thegasification reaction apparatus 201 includes therein the secondarygasification reaction pipe 203 and the primary gasification reactionroom 202 having a gasification agent supply line 303 linked to thesecondary gasification reaction pipe 203. The liquid fuel synthesisapparatus 1 is structured, as described above, so that the reactors 2(not shown in FIG. 5) and the coolers 3 (not shown in FIG. 5) arearranged in a serial manner. The reactor 2 and the cooler 3 areconnected to each other via the synthetic gas supply pipe 4 (not shownin FIG. 5) and the reaction gas derivation pipe 5 (not shown in FIG. 5).The cooler 3 (not shown in FIG. 5) includes the liquid fuel collectionpipe 6 (not shown in FIG. 5).

The biomass supply hopper 205 is connected to the gasification reactionapparatus 201 by being connected to the primary gasification reactionroom 202 via a biomass supply line 204. The gasification reactionapparatus 201 is connected to the liquid fuel synthesis apparatus 1 viathe synthesis raw material gas supply line A. The biomass supply line204 is composed of a transfer means such as a belt conveyor or a screwfeeder.

In this apparatus, clean high-temperature combustion gas 109 having atemperature exceeding 900 degrees C. that is generated frombiomass-ground fuel by a high-temperature hot gas generation apparatus101 is sent to the gasification reaction apparatus 201. Then, theprimary gasification reaction room 202 in the gasification reactionapparatus 201 and the secondary gasification reaction pipe 203 connectedthereto are heated by heating the outer wall face.

In this example, the primary gasification reaction room 202 receives theoverheat water vapor from the bottom section, wherein the overheat watervapor is generated by a waste heat boiler 301 out of emission gas 215and also receives coarsely-ground biomass from the upper section,through the biomass supply line 204. In the primary gasificationreaction room 202, the coarsely-ground biomass and overheat water vaporfunctioning as a gasification agent absorb, as chemical reaction heat,radiation heat from the wall of the gasification reaction room tothereby provide gasification including a overheat water vapor reformingreaction without using a catalyst.

The synthetic gas generated in the primary gasification reaction room202 further promotes the gasification reaction of tar and soot includedtherein. Thus, the synthetic gas is sent to the secondary gasificationreaction pipe 203 and is subsequently sent as synthetic gas to a fuelgas tank 404 and is temporarily stored. The secondary gasificationreaction pipe 203 and the fuel gas tank 404 have therebetween a heatexchanger 401 for collecting heat waste, cyclone 402 for removing ashand soot, a water spray scrubber 403 for removing residual water vapor,and a pressurization pump 405.

FIG. 6 is a schematic view illustrating the high-temperature hot gasgeneration apparatus 101. A combustion furnace 102 is structured to havea shaft furnace-type fixed floor and the lower part of the combustionfurnace has a fire grate 103. Biomass as a fuel is obtained by formingchips to have an appropriate shape of about 10 cm to drop the chipsthrough the top of the combustion furnace 102.

As combustion air, primary air 106 from the upper part, secondary air107 from the neighborhood of the fire grate 103, and tertiary air 108from the lower part of the fire grate 103 are supplied. The air orcombustion gas in the combustion furnace 102 is caused to flow in thelower direction because the discharged high-temperature combustion gas109 is induced by an induced draft fan at the downstream part to achimney pipe. By this method, the temperature of the combustion in thecombustion furnace reaches the highest combustion temperature in thevicinity of the upper part of the fire grate 103. The combustion gasincluding some combustible gas is completely combusted by the tertiaryair in a furnace bottom combustion room 111 under the fire grate in aclean manner.

The cleanliness levels of the gas property of the generatedhigh-temperature combustion gas 109 are shown in the following example.

Oxygen (O₂) 4.2%

Carbon dioxide (CO₂) 14.6%Hydrogen chloride (HCl) 430 ppmHydrogen sulfide (H₂S) 120 ppm

Hydrocarbon (CmHn) 0%

Carbon monoxide (CO) 0%Dioxin lower than detection limitCombustion temperature 1220 degrees C.

The high-temperature hot gas generation apparatus 101 has an airpreheater 110 that can heat the primary air 106, the secondary air 107,and the tertiary air 108 by 450 degrees C. at the maximum by thehigh-temperature combustion gas 109. Accordingly the high-temperaturehot gas generation apparatus 101 has a function to cause even biomasschips including 60% of water to be easily combusted. Further Thecombustion temperature in the fire grate 103 exceeds 1300 degrees C. andthus a structure for resisting such a high temperature is provided sothat the interior of the metal structure of the fire grate 103 is cooledby a part or the entirety of the secondary air 107 and then thesecondary air 107 is discharged as a combustion air through manysecondary air discharge orifices 104.

FIG. 7 is a schematic view illustrating the gasification reactionapparatus 201. The inner face of the outer wall of the gasificationreaction apparatus 201 is covered by heat insulation material 211. Thegasification reaction apparatus 201 includes therein the primarygasification reaction room 202 and the secondary gasification reactionpipe 203 connected thereto. Through the upper part of primarygasification reaction room 202, the coarsely-ground biomass is suppliedby dropping from the biomass supply hopper 205 via the biomass supplyline 204 (screw feeder in this example). On the other hand, from thebottom section of the primary gasification reaction room 202, theoverheat water vapor obtained by the waste heat boiler 301 is suppliedas biomass gasification agent 213. The high-temperature combustion gas109 is introduced via the high-temperature combustion gas supply line Bto the interior of the gasification reaction apparatus 201 to heat theprimary gasification reaction room 202 and the secondary gasificationreaction pipe 203.

In the primary gasification reaction room 202, chemical reaction betweenthe coarsely-ground biomass and the gasification agent 213 is caused bythe radiation heat from the wall of the reaction room, therebygenerating the synthetic gas 207 such as H₂, CO, CH₄, C₂H₄, and CO₂.

At the middle of the lower part in the primary gasification reactionroom 202, a porous plate 210 is provided that is made of a ceramicporous member or a punching copper plate for example. Thecoarsely-ground powder biomass about 3 mm or more remains on the porousplate 210 and is gasified for a long time. The generated synthetic gasgasified in the primary gasification reaction room 202 may include somesoot and tar.

Thus, the generated gas is sent to the secondary gasification reactionpipe 203 and the remaining soot and tar are redecomposed and gasified bythe gasification agent to obtain clean synthetic gas that is used asfuel gas.

FIG. 8 illustrates a comparison of the composition between the syntheticgas by the floating gasification of the microparticle biomass and thesynthetic gas by the gasification of the coarse powder biomass on theporous plate 210 in the biomass gasification apparatus of the thirdembodiment for carrying out the present invention. The graph shown atthe lower side assumes carbonization gas composition of the syntheticgas as 100%. Since ethylene C₂H₄ means two carbon atomic molecules, thecomposition % was doubled to assume the total carbon gas as 100%.

The graph shown at the upper side illustrates a percentage of thegenerated hydrogen (H₂) to the carbonization gas 100%. Any of theresults were obtained by the gasification reaction room at 900 degreesC.

The amount of hydrogen (H₂) in the upper graph depends not only by thehydrogen in the biomass (e.g., C_(1.3)H₂O_(0.9)) but also by thereaction between the hydrocarbon gas of the biomass gasified componentand water vapor. For example, this can be represented by:C₂H₄+4H₂O→2CO₂+6H₂.

Thus, it can be assumed that the gasification reaction is promoted asthe hydrogen amount in the upper graph increases. As can be seen fromFIG. 8, in the gasification reaction in which biomass particles of 0.1mm, 0.6 mm, and 2.0 mm float in the gasification agent, the biomass ofsmaller particles can be gasified more easily while the biomass oflarger particles is suppressed from the promotion of the gasificationreaction. However, as can be seen from FIG. 8, even the coarse powderbiomass having a size of 10 mm can be subjected to the gasificationreaction equal to or higher than the floating gasification by causingthe biomass to remain on the porous plate to gasify the biomass. In thiscase, however, the biomass remaining on the porous plate requires a fewminutes of gasification reaction time while microparticles require thefloating gasification reaction of substantially 1 a second or less.

FIG. 9 shows an embodiment obtained by modifying the embodiment of FIG.5. In order to prevent the water vapor entering from the primarygasification reaction room 202 from condensing dew to cause anunnecessary load on the gasification reaction, the biomass supply hopper205 is linked to a coarse powder-accompanying gas supply line 206. Thecoarse powder-accompanying gas may be selected from among nitrogen gas,carbon dioxide, air, or the mixture thereof. When the biomass isaccompanied by the coarse powder-accompanying gas that has about 2 to15% weight ratio to the biomass in the case of carbon dioxide, about 2to 10% weight ratio in the case of nitrogen, and about 2 to 5% weightratio in the case of air, this can prevent the water vapor supplied tothe primary gasification reaction room 202 from entering the biomasssupply hopper 205, thereby preventing the humidification of the biomassin the biomass supply hopper 205. This can consequently reduce the lossof thermal energy in the gasification reaction apparatus 201, thusimproving the gasification efficiency.

The coarse powder-accompanying gas may be selected in consideration ofthe application of generated gas. For example, carbon dioxide isadvantageously used when the generated gas is used for methanolsynthesis. An appropriate amount of nitrogen mixed in the accompanyinggas has an effect of reducing water vapor. In considering for thecalorific value required to heat water enthalpy to an overheat watervapor enthalpy of a reaction temperature, nitrogen gas is preferablyused for a gas engine fuel application where a higher calorific value isprioritized. Another option is air for reasons of the availability ofnitrogen gas and cost.

In this embodiment, the external space of the primary gasificationreaction room 202 and the external space of the secondary gasificationreaction pipe 203 are divided by a heat-resistant partition wall 212 sothat the high-temperature combustion gas 109 can communicatetherethrough and the heat radiation between the primary gasificationreaction room 202 and the secondary gasification reaction pipe 203 canbe blocked.

By the partition wall 212, the high-temperature combustion gas 109 canbe supplied, in a prioritized manner, to the primary gasificationreaction room 202 requiring a higher temperature.

In addition to water vapor, gasification substitute gas (carbon dioxide)308 is supplied as a gasification agent from the gasification agentsupply line 303. Specifically, the gasification agent obtained by mixingthe overheat water vapor obtained by the waste heat boiler 301 with thegasification agent substitute gas 308 consisting of carbon dioxide issupplied via the gasification agent supply line 303 to the bottomsection of the primary gasification reaction room 202. Carbon dioxidehas some function as gasification agent at a high temperature. Carbondioxide however causes an increase in the carbon dioxide component inthe synthetic gas. When the synthetic gas is used for the synthesis ofmethanol, carbon dioxide in the synthetic gas is bonded to hydrogen togenerate methanol. This provides, when hydrogen can be supplied fromwater electrolysis by natural energy for example in particular, aneffect of significantly increasing the production amount of methanolsynthesis by the supply of carbon dioxide.

INDUSTRIAL APPLICABILITY

The present invention provides a new way to the use of biomass that isassumed as the most promising energy from the quantitative viewpointamong the renewable energy as a base for the sustainable societyexpected in the future. This technique may be widely used not only inJapan but also in foreign countries. Also according to the presentinvention, wood and grass having no competitive relation with food canbe gasified to thereby produce methanol in an industrial manner. Theresultant methanol can be used as biomass-derived methanol fuel, can befurther converted to bio diesel fuel, or also can be converted to otherchemical raw materials and thus has an extremely-wide industrialapplicability.

1. A process for production of liquid fuel from synthetic gas that isobtained by gasification of biomass and that includes hydrogen andcarbon monoxide, comprising: a first step of causing the synthetic gasto have a contact with catalyst while being pressurized at a pressure of0.5 to 5 MPa to synthesize liquid fuel gas; a second step of liquefyingthe liquid fuel gas to collect the gas to separate the gas fromunreacted synthetic gas; a third step of again causing the unreactedsynthetic gas to have a contact with catalyst while being pressurized ata pressure of 0.5 to 5 MPa to synthesize liquid fuel gas to subsequentlyliquefy the resultant liquid fuel gas to collect the gas to separate thegas from unreacted synthetic gas; and a fourth step of repeating thethird step.
 2. The process for production of liquid fuel according toclaim 1, wherein the liquid fuel is methanol.
 3. The process forproduction of liquid fuel according to claim 1, wherein the liquid fuelis liquid hydrocarbon.
 4. A liquid fuel synthesis apparatus, comprising:a plurality of reactors and a plurality of coolers that are arranged ina serial manner, wherein the reactors and the coolers are connected toone another via a synthetic gas supply pipe and a reaction gasderivation pipe, and the coolers include liquid fuel collection pipes.5. The liquid fuel synthesis apparatus according to claim 4, wherein aninlet-side of the synthetic gas supply pipe of the reactor has atemperature adjustment means.
 6. The liquid fuel synthesis apparatusaccording to claim 4, wherein the reactors are parallely arranged in aconstant temperature room in which a temperature can be adjusted.
 7. Theliquid fuel synthesis apparatus according to claim 4, wherein thereactor maintains the temperature of the interior at an appropriatetemperature by subjecting reaction heat generated by a syntheticreaction of the synthetic gas to a heat exchange with surroundingatmosphere.
 8. The liquid fuel synthesis apparatus according to claim 4,wherein a constant temperature room includes parallely-arranged reactorsfor maintaining the inner temperature at an appropriate temperature bysubjecting reaction heat generated by the synthetic reaction to a heatexchange with surrounding atmosphere.
 9. The liquid fuel synthesisapparatus according to claim 7 or 8, wherein an inlet of the syntheticgas supply pipe has a temperature adjustment means and a constanttemperature room includes the reactors for maintaining the innertemperature at an appropriate temperature by subjecting reaction heatgenerated by the synthetic reaction to a heat exchange with surroundingatmosphere, the reactors being parallely-arranged.
 10. The liquid fuelsynthesis apparatus according to claim 4, wherein the coolers subjectgas or liquid having a temperature equal to or lower than apredetermined temperature to a heat exchange.
 11. The liquid fuelsynthesis apparatus according to claim 4, wherein the coolers are storedin a cooling bath filled with cooling water having a predeterminedtemperature or less.
 12. The liquid fuel synthesis apparatus accordingto any of claims 4 to 11, wherein the liquid fuel is methanol.
 13. Theliquid fuel synthesis apparatus according to any of claims 4 to 11,wherein the liquid fuel is liquid hydrocarbon.
 14. A liquid fuelproduction apparatus, comprising: a biomass supply hopper; agasification reaction apparatus; and a liquid fuel synthesis apparatus,wherein the gasification reaction apparatus includes therein a secondarygasification reaction pipe and a primary gasification reaction room thathas a gasification agent supply line linked to the secondarygasification reaction pipe, the liquid fuel synthesis apparatus iscomposed of a plurality of reactors and a plurality of coolers that arearranged in a serial manner, the reactors and the coolers are connectedto one another via a synthetic gas supply pipe and a reaction gasderivation pipe, and the coolers include liquid fuel collection pipes,the biomass supply hopper is connected to the gasification reactionapparatus by being connected to the primary gasification reaction roomvia a biomass supply line, and the gasification reaction apparatus isconnected to the liquid fuel synthesis apparatus via a synthesis rawmaterial gas supply line.
 15. The liquid fuel production apparatusaccording to claim 14, wherein the biomass supply hopper includes acoarse powder-accompanying gas supply line.